This jail which was in service for over a century is now open for curious visitors.

This Pennsylvania cave holds evidence of the oldest known inhabitants of North America.

These disused steel furnaces are now haunting ruins that may one day be a national park.

This little-known Revolutionary War fort is supposedly haunted by the ghosts of its past.

Eccentric concrete mansion and museum designed and built by hand from the inside out.

"Dark Sky Park" is heaven on Earth for astronomers, one of the rare U.S. locations with no artificial light pollution.

On the Oregon coast there is a natural hole that seems to be draining the sea.

A crumbling hospital from the 1850s on Roosevelt Island.

The highest point in Alabama was almost completely deforested, but is now home to protected towers and trees.

The only Florida state park with publicly accessible caves.

This former maximum-security prison is creepy, sobering, and supposedly haunted.

These early tent-shaped grave coverings are unique to Appalachia.

A museum celebrating rare American motorcycles where everything runs—and none of it quietly.

For two weeks every June, fireflies in the Smoky Mountains perform an astonishing light show.

One man’s religious convictions led him to build this stone castle meant to withstand an apocalypse.

This Transylvania County city is home to a rare white squirrel population that is descended from an escaped carnival animal.

An abandoned town is hidden in Great Smoky Mountains National Park.

According to local lore, this narrow passageway through two large rocks was accidentally created by the devil himself.

This limestone outcropping was once a ceremonial site for ancient Native Americans.

The remains of the iconic train crash from the movie The Fugitive can still be found rusting along the Great Smoky Railroad.

This road in the Great Smoky Mountains was supposed to assuage a displaced community, but ended up a $52 million dead end.

Death comes to anyone who dares to touch this concrete column.

All you ever needed or wanted to know about America's favorite whiskey, but not a drop to drink.

This winding road of 318 curves is a must-visit for (careful) motorcycle and sports car enthusiasts.